1. Field of the Invention
The present invention relates to a method of forming a contact hole and a method of forming a semiconductor structure with contact plug, wherein more particularly, the contact hole and the semiconductor structure can be formed by a self-aligned contact (SAC) technology.
2. Description of the Prior Art
Semiconductor devices have been rapidly developed due to the wide use of information processing devices such as computers, and are typically required to have a large storage capacity and a high operation speed. To meet these requirements, semiconductor technology has been developed so that semiconductor devices have a high integration density, good reliability, and a high response speed.
As semiconductor devices become more highly integrated, the width of interconnections and spacing between interconnections have also been reduced. Self-aligned contact technology has been used to increase alignment margins when using a photolithography technique to form contact holes in predetermined regions between the interconnections. However, by using the conventional self-aligned contact technology, the cap layer and the spacer of a transistor will be over etched, therefore, current leakage may occurred.